Development of freezing tolerance in roots and shoots of Scots pine seedlings at nonfreezing temperatures

1998 ◽  
Vol 28 (4) ◽  
pp. 557-565 ◽  
Author(s):  
Aija Ryyppö ◽  
Tapani Repo ◽  
Elina Vapaavuori
Keyword(s):  
Plasma Membrane ◽  
Low Temperature ◽  
Scots Pine ◽  
Fine Roots ◽  
Day Treatment ◽  
Growing Season ◽  
Frost Damage ◽  
Frost Hardiness ◽  
Pine Seedlings ◽  
Extracellular Resistance

The hardening of hydroponically cultured Scots pine (Pinus sylvestris L.) seedlings and their recovery after freezing was studied at the end of the second growing season (LD), after 3 weeks of short day treatment (SD), after a gradual decrease in temperature to 5°C over 4 weeks (H1), and after 4 weeks at 5°C (H2). Frost hardiness was determined by several methods and the recovery as survival of the seedlings. The highest frost hardiness was achieved in the distal parts of needles (-21 to -27°C) and in the proximal parts of needles (-18 to -25°C), followed by woody roots (-7 to -9°C), the 1-year-old and current stem (-8°C), and the fine roots (-5°C), all at the end of H2. Hardening of needles was induced by SD, but the stem and woody roots started to harden later, as a response to low temperature. As a result of frost treatment during LD and SD, potential plasma membrane roman H+-ATPase activity of roots decreased as electrolyte leakage increased and extracellular resistance decreased, but this relationship was lost during H1 and H2. The present study demonstrates the lack of hardening capacity in the fine roots of Scots pine seedlings at nonfreezing temperatures and the increased mortality of the young seedlings having frost damage on roots.

Frost damage and recovery of Scots pine seedlings at the end of the growing season

1997 ◽  
Vol 27 (9) ◽  
pp. 1376-1382 ◽  
Author(s):  
A Ryyppö ◽  
S Sutinen ◽  
M Mäenpää ◽  
E Vapaavuori ◽  
T Repo
Keyword(s):  
Scots Pine ◽  
Growing Season ◽  
Frost Damage ◽  
Pine Seedlings

The relationship between multiple leaders and mechanical and frost damage to the apical meristem of Scots pine seedlings

1990 ◽  
Vol 20 (3) ◽  
pp. 280-284 ◽  
Author(s):  
Jarmo K. Holopainen
Keyword(s):  
Scots Pine ◽  
Apical Meristem ◽  
Dry Weight ◽  
Frost Damage ◽  
Night Temperature ◽  
Shoot Dry Weight ◽  
Frost Injury ◽  
Pine Seedlings ◽  
Before And After ◽  
Multiple Leaders

The responses of young Scots pine seedlings to mechanical apical meristem damage before and after 4 nights exposure to minimum night temperatures of −2.2 and −6.7 °C in controlled environment growth chambers were compared with control seedlings that were subjected or not to apical meristem damage and exposed to a minimum night temperature of 12 °C. The feeding damage caused by Lygus bugs was simulated by piercing the apical meristem of young pine seedlings with a hypodermic syringe needle and injecting a small drop of distilled water into the wound. At −6.7 °C increased numbers of dead seedlings were found. The proportion of seedlings with multiple leaders greatly increased after piercing, and about half of the seedlings subjected to the apical meristem damage had multiple leaders. The proportion of seedlings with multiple leaders and the number of leader shoots per seedling did not differ among seedlings subjected to apical meristem damage before or after the frost exposure. Short and twisted primary needles occurred in the basal parts of the new shoots in the seedlings with multiple leaders. Seedlings with necrotic needles were most often found after exposure to the night temperature of −6.7 °C. Shoot dry weight and length were significantly lower in seedlings subjected to apical meristem damage after frost exposure than in seedlings subjected to apical meristem damage before frost exposure or to no frost exposure. The results suggest that an increased reduction in growth is to be expected if Lygus bug attacks occur on pine seedlings that already suffer from frost injury.

Nitrate metabolism in Scots pine seedlings during their first growing season

1987 ◽  
Vol 3 (3) ◽  
pp. 285-293 ◽  
Author(s):  
T. Sarjala ◽  
R. Raitio ◽  
E.-M. Turkki
Keyword(s):  
Scots Pine ◽  
Growing Season ◽  
Pine Seedlings ◽  
Nitrate Metabolism

Some observations on the shoot growth of pine seedlings

1976 ◽  
Vol 6 (3) ◽  
pp. 341-347 ◽  
Author(s):  
S. Thompson
Keyword(s):  
Scots Pine ◽  
Shoot Apex ◽  
Shoot Growth ◽  
Lodgepole Pine ◽  
Growing Season ◽  
Pine Seedlings ◽  
Terminal Bud

Sequential observations in lodgepole pine (Pinuscontorta Dougl.) and Scots pine (P. sylvestris L.) showed that the second season's shoot was not produced solely from stem units in the terminal resting bud as previously assumed. The stem units held in the rosette of primary needles surrounding the terminal bud elongated to form most of the second season's shoot. The terminal bud only contributed 29 to 54% of the stem units. There was a marked difference between an inland and a coastal provenance of lodgepole pine in the appearance of the shoot apex at the end of the first growing season.

Shoot morphology and shoot growth potential in 1-year-old Scots pine seedlings

1981 ◽  
Vol 11 (4) ◽  
pp. 789-795 ◽  
Author(s):  
S. Thompson
Keyword(s):  
Scots Pine ◽  
Shoot Growth ◽  
Growing Season ◽  
Shoot Elongation ◽  
Growth Potential ◽  
Shoot Morphology ◽  
Growing Seasons ◽  
Pine Seedlings

When seedlings of a single seed source of Scots pine (Pinussylvestris L.) were raised for 26 weeks in a naturally lit, heated greenhouse, two types of shoot morphology were observed. Type 1 was that normally found in 1-year-old seedlings. Type 2 had a shoot morphology similar to that of seedlings raised outdoors for two growing seasons. When compared with type 1 plants, type 2 plants had an earlier start to shoot elongation, set their buds earlier, and stopped shoot elongation sooner. After one growing season, type 2 plants were shorter, had fewer stem units for shoot elongation in the second season, but carried a greater foliage biomass than 1-year-old type plants. After two seasons they remained shorter. Thus, plant rearing practices which result in the production of seedlings with this type of shoot morphology arc undesirable.The relationship between early "budsct," shoot morphology, and plant height suggests that the proportion of seedlings with a 2-year-old shoot morphology after one growing season in a heated greenhouse may be used as an early test for height growth potential in seed origins and possibly in progenies of north temperate pine species.

Dynamics of fine-root production and mortality of Scots pine in waterlogged peat soil during the growing season

2020 ◽  
Vol 50 (5) ◽  
pp. 510-518
Author(s):  
Tapani Repo ◽  
Timo Domisch ◽  
Jouni Kilpeläinen ◽  
Sirpa Piirainen ◽  
Raimo Silvennoinen ◽  
...  
Keyword(s):  
Scots Pine ◽  
Tree Growth ◽  
Root Length ◽  
Fine Roots ◽  
Time Course ◽  
Fine Root ◽  
Peat Soil ◽  
Growing Season ◽  
Root Production ◽  
Fine Root Length

Excess water in the rooting zone critically reduces tree growth and may even kill trees; however, the relative importance of damage to roots versus aboveground parts and the time course of damage are not well understood. We studied the dynamics of fine-root growth and mortality of 7-year-old Scots pine (Pinus sylvestris L.) saplings affected by a 5-week period of waterlogging (WL) during the growing season. Two out of six WL-exposed saplings survived the treatment. After 1–2 weeks of WL, the mortality of the first-order short roots (usually mycorrhizas) started to increase and the production of these roots started to decrease. WL decreased the longevity of short and long roots. Total root length (especially of fine roots with a diameter < 0.5 mm), specific fine-root length, total root dry mass (including stump), and reverse-flow root hydraulic conductance were lower in WL saplings than in control saplings at the end of the experiment; however, several root traits were similar in control and surviving WL saplings. Because of the high importance of fine roots for tree growth and carbon sequestration, their responses to elevated water tables should be considered in sustainable use and management of boreal peatland forests, for example, by continuous cover forestry and (or) ditch network maintenance.

Atmospheric CO2 enrichment and the development of frost hardiness in containerized black spruce seedlings

1990 ◽  
Vol 20 (9) ◽  
pp. 1392-1398 ◽  
Author(s):  
Hank A. Margolis ◽  
Louis-P. Vézina
Keyword(s):  
Black Spruce ◽  
Co2 Enrichment ◽  
Growing Season ◽  
Frost Damage ◽  
Development Stage ◽  
Frost Hardiness ◽  
Mineral Nutrient ◽  
Experimental Conditions ◽  
Frost Injury ◽  
Controlled Freezing

The hypothesis that a relatively brief exposure to elevated atmospheric CO2 could increase the frost resistance of shoots was tested on containerized black spruce seedlings (Piceamariana (Mill.) B.S.P.). Seedlings were exposed to 1000 ppm CO2 toward the end of their second growing season in an unheated production tunnel and in a heated greenhouse. In 1987, continuous 10-week CO2 exposures were applied in conjunction with mineral nutrient fertilization, and freezing tests were conducted each week. In 1988, a series of shorter 2-week CO2 exposures was applied to different groups of seedlings and no mineral nutrients were added. Controlled freezing tests were conducted at −10 °C and were followed by electrolytic conductivity measurements to assess frost injury. Under all experimental conditions, freezing tests on seedlings from both the production tunnel and the greenhouse indicated significantly greater frost damage for the CO2-enriched seedlings than for the controls. Late-growing season CO2 enrichment negatively affected the bud initiation – bud development stage of frost-hardiness development.

Seasonal development of Scots pine under climatic warming: effects on photosynthetic production

2005 ◽  
Vol 35 (9) ◽  
pp. 2092-2099 ◽  
Author(s):  
Heikki Hänninen ◽  
Pasi Kolari ◽  
Pertti Hari
Keyword(s):  
Solar Radiation ◽  
Computer Simulations ◽  
Scots Pine ◽  
Frost Damage ◽  
Frost Hardiness ◽  
Seasonal Development ◽  
Climatic Warming ◽  
Present Climate ◽  
First Approximation ◽  
Photosynthetic Production

In boreal conditions under climatic warming, photosynthesis will start earlier in the spring than it does in the present climate. As a first approximation this phenomenon would increase the annual photosynthetic production of boreal conifers, as they can use the high amounts of incoming solar radiation prevailing during spring to a greater extent than in the present climate. However, the recovery of photosynthesis is accompanied by a simultaneous dehardening of the needles. Thus, climatic warming may also cause a premature dehardening of the needles during spring. This may result in needle losses caused by frost damage; so climatic warming may also decrease the annual photosynthetic production of boreal conifers. Using computer simulations with ecophysiological models, these counteracting effects of climatic warming on photosynthetic production were studied in Scots pine (Pinus sylvestris L.) trees growing in southern Finland. The results show that because of our insufficient understanding of the environmental regulation of frost hardiness, it is not possible to conclude which one of the two potential effects will dominate under climatic warming. This finding calls for further empirical development and testing of the frost hardiness models.

scholarly journals A descriptive model o Scots pine (Pinus silvestris) L. seedling's growth during the first growing season

2015 ◽  
Vol 45 (1–2) ◽  
pp. 143-158
Author(s):  
Teresa Gowin ◽  
Leokadiusz Ubysz
Keyword(s):  
Scots Pine ◽  
Dry Matter ◽  
Growth Curves ◽  
Dry Weight ◽  
Growing Season ◽  
Logistic Growth ◽  
Descriptive Model ◽  
Relative Growth ◽  
Pine Seedlings ◽  
Net Assimilation

Scots pine seedlings were grown in pots from seed under outside conditions. Plant material was harvested ten times in fortnight periods, throughout the growing season. At each harvest, each plant was divided into particular organs and their dimensions as well as fresh and dry weight were determined. Seasonal course of growth of particular organs as well as changes in specific leaf area and distribution of dry matter between shoot and root were investigated. Net assimilation rate (NAR) and relative growth rate (RGR) were calculated from the fitted logistic growth curves.

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